Federal prosecutors said a West Brookfield man has been sentenced to 10 years in prison for his second conviction of possessing child pornography. Christopher Boucher, 44, pleaded guilty Tuesday in federal court in Springfield to possession of material involving sexual exploitation of a minor. His sentence includes 10 years of supervised release with special conditions for sex offenders. Prosecutors said State Police found a laptop a year ago at Boucher’s former home in Ware that contained video showing multiple rapes of a young girl. Boucher was sentenced in 2001 to five years’ probation and six months home detention after pleading guilty to possession of child pornography.